A mobile communication system is typically consisted of a User Equipment (UE), a radio access network and a core network. Particularly an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) is a radio access system consisted of (evolved) Node B's ((e)NB's) connected with each other. An Evolved Packet Core (EPC) is a core network system, and the EPC includes a Home Subscriber Server (HSS), a Mobility Management Entity (MME) and a Gateway (GW), where the HSS is configured to store subscription data of subscribers, the MME is configured to perform mobility management on the UE, and the gateway is configured to perform functions of storing, forwarding and routing user plane data of the UE.
In a scenario where UEs communicate with each other, the UEs have to communicate with each other through relay and proxy functions available from the eNB and the gateway.
There is centralized control by the network in a Long Term Evolution (LTE) system, that is, both uplink and downlink data of a UE is transmitted and received under the control by the network, but there is no direct communication link between one UE and another, so the UEs have to communicate with each other through forwarding, and under the control, by the network and the UEs are not allowed to transmit uplink data by themselves, as illustrated in FIG. 1.
In the prior art, pure Device to Device (D2D) communication refers to direct communication between one UE and another through Bluetooth, Wireless Fidelity (WiFi), etc., over an unlicensed frequency band resource, and such D2D communication involving behaviors of subscribers themselves without being managed and controlled by a network operator can only be applied in a limited number of scenarios.
In another scheme, the D2D technology is introduced to the mobile communication operator network, and in this scheme, some direct communication is allowed between UEs so that one UE can obtain information directly from the other UE in the D2D scheme over direct communication links which can be set up under the control or assistance by the network, and D2D communication is performed between the UEs by discovering a proximate UE. As illustrated in FIG. 2, an evolved Node B (eNodeB) sets up uplink/downlink communication links respectively with a UE 1 and a UE 2 under the control by a Core Network (CN) to configure the UE 1 and the UE 2, and the two configured UEs can perform D2D communication based upon configuration information.
There has not yet been defined in the prior art a solution to controlling a UE capable of proximity awareness.